Yea, there is definitely a big difference, for example between someone who is high and someone who is drunk while operating a vehicle. The drunk person loses perception, motor-skills, reflexes while a stoned person just gets paranoid and tries to get home as fast as he can 10 miles under the speed limit with his bag of Dorritos

It's almost scary how true that is. Although a lot has to do with how many times they have done it.